In these days, researches and developments have been energetically made on various display elements using organic fluorescent materials (organic luminous elements). Among all, organic EL elements have attracted public attention as display elements with a potential capability of achieving luminescence with a high luminance at a low voltage. For example, it is reported to construct an EL element by forming an organic thin layer through deposition of organic compounds (Applied Physics Letters, vol. 51, p. 913, 1987). The organic EL elements disclosed in this report have a laminated structure of an electron-transporting material and a hole-transporting material and thus show highly improved electroluminescence characteristics compared with the conventional elements of the single-layer type.
Because of being formed by the deposition method, however, the above-mentioned EL elements suffer from difficulties in the area-enlargement and productivity. Taking these points into consideration, it has been required to establish a process for producing EL elements by the advantageous coating method. Known examples of EL element materials which can be used in producing EL elements by the coating method include paraphenylene vinylene polymers (Advanced Materials, p. 4, 1992). Although EL elements containing these conjugated polymers can achieve luminescence with a high luminance, the polymer compounds disclosed in the above literature can exclusively give green to red luminescence. To supply full-color EL elements and achieve white luminescence, it has been therefore required to develop conjugated polymer compounds capable of giving blue luminescence.